A report on an anechoic room design using metal wedges

Abstract

An anechoic room is important in acoustic measurements to simulate free-field conditions. The room is designed with walls that are covered with wedges that absorb as much sound as possible to eliminate reflections. Conventional wedges are constructed from a high-density sound-absorbing material such as rock wool and attached to a wire frame to maintain the shape of the wedges. However, these wedges are fragile and easily deformed by physical disturbances. In this paper, a design of an anechoic room using metal wedges is presented. Glass wool with a density of 32 kg/m3 is enclosed within a perforated metal casing, which provides durability and resistance to physical disturbances. The wedges are installed in a room with a dimension of 6.17 m × 5.87 m × 4.85 m. It is shown in a performance assessment based on ISO 3745 that wedges are capable of absorbing sound well, thus allowing sound to propagate according to the inverse square law. Additionally, a comparison study of the absorption performance of glass wool wedges compared to metal wedges is discussed with a view to improving the system in the future.